METHOD FOR METHOD FOR DETECTION OF SURFACE FLAWS OF MOVING STRIP AND DEVICE FOR IMPLEMENTATION OF SAID METHOD

摘要

FIELD: measuring devices. SUBSTANCE: each value of video signal is adjusted by compensation of decreasing modulation gain coefficient for high frequencies which correspond to low size flaws. Tested surface is scanned by linear video signal generator to achieve this goal. Each value of generated video signal is stored during line sweep period. Simultaneously video signal range from black to white background is divided into equal pieces and number of video signal samples which are in each piece is counted. Signals are added during time range between moment when signal enter given piece and moment when signal leave it. Factors are assigned for each sum according to dependency which was determined from previous investigations. During next stage, each value of delayed video signal is corrected by multiplication by corresponding factors. Noise signals represented as high- frequency alterations of video signal are filtered in the following way. If time when video signal level belongs to some piece is less then given minimal value, it is regarded as noise and corresponding assigned factor is 1. Corrected video signals are averaged by several lines for each element of video signal generator. Resulted value is cleared after some time intervals. Average values are compared to current values of video signal and flaws are detected by results of this comparison. Device implementing said method has video camera 1, video signal correction unit 2, averaged value calculation unit 3, comparison unit 4, decision making unit 5. EFFECT: increased functional capabilities. 2 cl, 1 dwg